Endangered Species Act Five-year Review and Recovery Plan Updates for US Smalltooth Sawfish, Pristis pectinata.

By Tonya Wiley-Lescher (Haven Worth Consulting)

The United States distinct population segment (DPS) of Smalltooth Sawfish (Pristis pectinata) was classified as Endangered under the US Endangered Species Act (ESA) in 2003. Recently I was contracted by NOAA Fisheries (National Marine Fisheries Service) to draft two key documents regarding the US population of Smalltooth Sawfish. 

The first document is an ESA 5-year review. To monitor recovery efforts and ongoing threats to the species, the ESA requires the status of the species be assessed through regular 5-year reviews. A 5-year review is an analysis conducted to determine if the current listing classification under the ESA is still accurate. The first review was completed in 2010 and, based on criteria established in the recovery plan, determined the species still warranted protections afforded by an Endangered classification. Our scientific knowledge of the species has grown considerably since then. So I am compiling all we have learned about this species of sawfish in the US, to determine if any recovery goals have been met. The second ESA 5-year review will, again, determine if the listing classification of Endangered under the ESA is still appropriate.

The second document is an updated Recovery Plan. A recovery plan for the US DPS of Smalltooth Sawfish was published in 2009 detailing goals and actions necessary to meet identified recovery criteria. Recovery plans serve as road maps for species recovery - they lay out where we need to go and how best to get there. Changes to the recovery plan, including revised recovery goals and criteria, are also underway. Updating the plan, and the recovery criteria it contains, will help scientists and managers work toward restoring the sawfish population in the US to the point where it is a secure part of its ecosystem and protections under the ESA are no longer needed. The US Smalltooth Sawfish Implementation Team will meet in April 2016 to finalize the updated plan and submit it to NOAA Fisheries to be reviewed and published. 

Tonya releasing a Smalltooth Sawfish pup.

To ensure these documents are based on the best available scientific and commercial data, public comments regarding US Smalltooth Sawfish can be submitted until March 22, 2016. I will be presenting the results of the second 5-year review and the updated recovery plan at the Biology and Ecology of Sawfishes symposium at the American Elasmobranch Society meeting in New Orleans this July. 

For more information on smalltooth sawfish, the Endangered Species Act, and US recovery efforts visit http://sero.nmfs.noaa.gov/protected_resources/sawfish/index.html

Team Sawfish: the extreme highs and lows of 2015

Team Sawfish’s 2015 was a year of extremes, not only for us researchers, but also for the sawfishes we study in Western Australia. Beginning the year with one of the driest wet seasons in the last 15 years, we knew we were likely to find low water levels and few young of the year sawfish, but we could not have imagined what surprises, good and bad, were in store for us.

Team Sawfish 2015. Dr David Morgan not pictured. Photo: Jeff Whitty

Our adventures began in early August, the early dry season, in the lower estuarine pools of the Fitzroy River. This time of the year is often ideal as the days are warm, nights are cool and rain is absent. By August, river discharge has fallen and the once flowing river is transformed into a chain of isolated pools. The small amount of river flow that remains and the relatively cold air temperatures keep the estuarine pools fresh and cool, with only the occasional spike in salt when the tidal waters intrude from nearby King Sound.  

The lower estuarine pool where we captured Dwarf Sawfish in August 2015. Photo: Jeff Whitty

 

During this early dry season excursion, we set out to continue our research on the Largetooth (Freshwater) Sawfish. However, the sawfish had other plans, as only Dwarf Sawfish, a marine species, were present. One after another, these fish filled our nets, an unusual occurrence for any sawfish species. We were not only surprised by the presence and numbers of the Dwarf Sawfish, but also by the salinity levels of the water, which were unusually high, being close to that of sea water, and the likely reason for the presence of the Dwarf Sawfish.

Knowing to never let a good opportunity pass us by, we decided to make lemon-aid from this lemon of a situation and tagged these Dwarf Sawfish with acoustic transmitters; a project (in collaboration with CSIRO) that was not due to start until October. This opportunity allowed for us to commence our study early, and collect months of data that we would have otherwise missed out on.  After deploying all of the tags that we had with us at the time, we departed with plans to continue to take advantage of this situation during our next field trip.

A Dwarf Sawfish tagged and released by Team Sawfish in the Fitzroy River in 2015. Photo: David Morgan

Returning in September, we once again were successful in finding large numbers of Dwarf Sawfish, at one point catching eleven within a single hour. Other fishers were also reporting unusual captures of marine fishes within the lower regions of the river, including hammerhead (likely Winghead) and Blacktip Sharks. We even had a surprise catch of our own. While fishing in the estuarine pools, we were ecstatic to catch the first ever Green Sawfish to be recorded within the Fitzroy River! Although we have observed Green Sawfish to use river mouths as nurseries, captures of this species in the King Sound are rare. 

Dr David Morgan with the Green Sawfish. Photo: James Keleher

Moving our efforts to the freshwater pools further upriver, we resumed our search for the Largetooth Sawfish. Despite high levels of effort, we encountered relatively few sawfish, a common trend over the last few years (likely due to the short wet seasons that have occurred during the same period). As the wet season size dictates the depth of the river, it also dictates how many sawfish can make their way to the safety and stability of the freshwater pools, and how many young of the year are recruited into the riverine nursery. As this dry spell has lasted several years, the only Largetooth Sawfish we observed in 2015 were those pupped in 2011. 

A sawfish cake. One of the few Largetooth Sawfish we saw on this trip.

In early December, our team found itself on the river once again, but this time amongst an unfortunate situation. Our team was informed by local residents that there had been a large die-off of sawfish and Bull Sharks in the upper reaches of the Fitzroy River.

Upon arriving at the site, the stench of death filled our noses and swarms of flies covered our faces. With the help of the locals, we recovered 12 Largetooth Sawfish, 8 Bull Sharks and a Whiptail Stingray, while also observing deceased catfish, cherabin (crayfish) and thousands of mussels floating on the surface of the water. Even arriving only a couple days after the deaths of the fishes, the now extreme heat and local scavengers had started to break down their bodies, making any autopsy and sampling of these animals near impossible. Despite the conditions, we collected what salvageable information we could, to ensure that this tragedy was not a total waste. 

Some of the Largetooth Sawfish and Bull Sharks killed by the low dissolved oxygen event in December. Photo: Jeff Whitty

Unable to determine the cause of death from the animals themselves, we turned to the environment to see if there was any evidence to suggest what happened. We deployed multiple sensors throughout the entirety of the affected pool to detect any abnormalities in the temperature, oxygen levels and pH of the water column; it was not long before we had identified the silent killer. There was very little oxygen below a depth of 1 meter and no oxygen below 2 m in this 10+ m deep pool. From interviews with local residents, we learned that a small rain event had washed oxygen-hungry organic matter into the pool. Without the additional input of freshwater, this organic sludge became concentrated within the single pool and likely absorbed the dissolved oxygen in the water, killing all bottom dwelling species. Similar occurrences have taken place in other seasonally flowing rivers in Australia but thankfully, residents said that this is a rare event in the Fitzroy River.

All in all, 2015 was an eventful year for the sawfishes of the Fitzroy River and Team Sawfish. Although we faced an number of unfortunate events, these unusual occurrences provided us with insight into how changes to the climate and environment can impact various species of sawfishes. As we move on to a new year of research, we are hoping to find a long and rainy wet season and a new batch of young of the year sawfish awaiting for us around the riverbend.

For more information about Team Sawfish and our work, please visit www.freshwaterfishgroup.com or like our Facebook page at https://www.facebook.com/Freshwater-Fish-Group-Fish-Health-Unit-342655079102312/?fref=ts. We would like to thank the Western Australia Marine Science Institute, Chevron Australia and CSIRO for funding these projects.

First Nation-Wide Survey Shows Hope for Sawfishes in Mexico

Stage I of the first-ever survey for sawfishes in Mexico (and in fact, the first research project ever devoted to this threatened group of fishes in the country) was just completed by Océanos Vivientes casting a grey shadow on the outlook for sawfish conservation in the country… But a new ray of hope just emerged!

Personnel of Project Pristis Mexico interviewing fishermen 
during the nation-wide survey.

Through its “Project Pristis Mexico” (Proyecto Pristis México in Spanish), personnel of Océanos Vivientes, a Mexican NGO devoted to the research and conservation of sharks and rays, visited 71 fishing locations along the Pacific, Gulf of Mexico, and Caribbean coasts of Mexico. During a survey that involved driving over 10,500 km and talking to over 800 fishermen, Océanos Vivientes interviewed more than 250 fishermen who had witnessed encounters with either the smalltooth (Pristis pectinata) or largetooth (P. pristis) sawfishes.

“The results of the first stage of this project offered a worrying panorama for sawfish conservation” stated Ramón Bonfil, Executive Director of Océanos Vivientes, and PI of Project Pristis Mexico. “Most fishermen reported never having seen a sawfish dead or alive, and those who had were mostly old fishermen on the 60-70 year old range, an indication of how long ago sawfishes became rare in Mexico” he added. However the most worrying result was that the scientists could not find substantiated reports of live specimens anywhere in the country. A small number of fishermen on both coasts reported having seen sawfishes either a few months or a few years ago, but there was no way to scientifically confirm these claims (such as photographs).

Océanos Vivientes scientists measuring a sawfish rostrum.

Despite this gloomy outlook, Océanos Vivientes remained hopeful that somewhere, someone would report a live specimen through the communications network they had built during the four months they spent in the field. “Our hopes and hard work were rewarded yesterday morning, when the first confirmed report of a live smalltooth sawfish came to us through a phone call from a fisherman”, Bonfil remarked. 

Fisherman reading information poster distributed by Océanos Vivientes
throughout the country.

The first smalltooth sawfish seen in Mexico since 2005 (the team's interview surveys confirmed that the last report of this species in Mexican waters was caught in Tamaulipas state in 2005) was accidentally caught in a snook gillnet in the State of Veracruz by fisherman Constantino Correa, who swiftly reported the finding to Océanos Vivientes. The sawfish, a juvenile female 1.54 m long, was kept alive, measured and photographed by the fisherman, and the information they collected was sent to the scientists. This was made possible thanks to the grassroots work that Océanos Vivientes has carried out around the country in recent months. “This important finding means that there are still a few sawfish in Mexico and that we must intensify efforts to protect them and help their populations recover and be again as plentiful as they were 60 years ago” said Bonfil. 

The female smalltooth sawfish (Pristis pectinata) found alive in Veracruz
state.

The discovery of this sawfish is an event of enormous significance for the conservation outlook of sawfishes. It crowns the efforts that Project Pristis Mexico has devoted over the last 6 months, and shows that contrary to previous assumptions, sawfish are still present in Mexico. However, it is likely that they are very close to local extinction, which means that both government and society at large need to rapidly increase efforts and make more resources available for the conservation and protection of sawfishes in Mexico. Having definitive evidence that there are still sawfish living in Mexico means there is still a chance that wild populations could be adequately protected and brings hope for their long-term recovery.

Personnel from the Veracruz Aquarium collected the juvenile sawfish and took it to their facilities where it is still in recovery and under observation. It is hoped that a properly planned captive reproduction program can be developed in the future (once a male of the species is found and brought to the same aquarium).

The second stage of Project Pristis Mexico, to be launched as soon as new grants are obtained, plans to expand surveys to other parts of the country and locations that could not be visited before. However the most important new aims are to actively look for sawfishes in specific locations identified through Stage I of the project, launch a tracking program using satellite tags, and involve the fishing communities in the protection of sawfishes and their coastal habitats in order to guarantee the recovery of the populations. 

Dr. Ramón Bonfil giving an environmental education talk about sawfishes
to a group of fishermen.

For more information visit Proyecto Pristis Mexico Facebook page at  https://www.facebook.com/ProyectoPristisMexico/.